The Rist radial access system: a multicenter study of 152 patients.

BACKGROUND: Transradial access (TRA) for neurointervention is becoming increasingly popular as experience with the technique grows. Despite reasonable efficacy using femoral catheters off-label, conversion to femoral access occurs in approximately 8.6-10.3% of TRA cases, due to an inability of the catheter to track into the vessel of interest, lack of support, or radial artery spasm. METHODS: This is a multicenter, retrospective case series of patients undergoing neurointerventions using the Rist Radial Access System. We also present our institutional protocol for using the system. RESULTS: 152 patients were included in the cohort. The most common procedure was flow diversion (28.3%). The smallest radial diameter utilized was 1.9 mm, and 44.1% were performed without an intermediate catheter. A majority of cases (96.1%) were completed successfully; 3 (1.9%) required conversion to a different radial catheter, 2 (1.3%) required conversion to femoral access, and 1 (0.7%) was aborted. There was 1 (0.7%) minor access site complication and 4 (2.6%) neurological complications. CONCLUSIONS: The Rist catheter is a safe and effective tool for a wide range of complex neurointerventions, with lower conversion rates than classically reported.

Management of acute orbital hemorrhage with obstruction of the ophthalmic artery during attempted coil embolization of a dural arteriovenous fistula of the cavernous sinus.

Because of inability to access a cavernous-carotid fistula through conventional means, a superior ophthalmic vein approach was used to allow access for embolization. Although there was initially robust flow through both the fistula and the ophthalmic artery on angiography, the flow stopped during the procedure, and the patient was found to have an orbital hemorrhage. Immediately on emergent canthotomy and evacuation of the hemorrhage, angiographic evidence of restoration of flow was noted. This finding suggests that vision loss in orbital compartment syndrome may be due to arterial occlusion in some cases, and may be reversible if prompt action is taken.

Microglia cyclooxygenase-2 activity in experimental gliomas: possible role in cerebral edema formation.

PURPOSE: Cerebral edema is responsible for significant morbidity and mortality in patients harboring malignant gliomas. To examine the role of inflammatory cells in brain edema formation, we studied the expression cyclooxygenase (COX)-2, a key enzyme in arachidonic acid metabolism, by microglia in the C6 rodent glioma model. EXPERIMENTAL DESIGN: The expression of COX-2 in primary microglia cultures obtained from intracranial rat C6 gliomas was examined using reverse transcription-PCR, Western analysis, and prostaglandin E(2) (PGE(2)) enzyme immunoassay. Blood-tumor barrier permeability was studied in the same tumor model using magnetic resonance imaging. RESULTS: In contrast to C6 glioma cells, microglia isolated from intracranial C6 tumors produced high levels of PGE(2) through a COX-2-dependent pathway. To test whether the observed microglia COX-2 activity played a role in brain edema formation in gliomas, tumor-bearing rats were treated with rofecoxib, a selective COX-2 inhibitor. Rofecoxib was as effective as dexamethasone in decreasing the diffusion of contrast material into the brain parenchyma (P = 0.01, rofecoxib versus control animals), suggesting a reduction in blood-tumor barrier permeability. CONCLUSIONS: These findings suggest that glioma-infiltrating microglia are a major source of PGE(2) production through the COX-2 pathway and support the use of COX-2 inhibitors as possible alternatives to glucocorticoids in the treatment of peritumoral edema in patients with malignant brain tumors.